Exemplary embodiments of the present invention relate to a spatial light modulator, particularly a liquid crystal type spatial light modulator, and to a projector disposed with the spatial light modulator.
The related art has expanded the home use of projectors. For this reason, it would be advantageous for spatial light modulators in projectors to be inexpensive, to have a long life and high light use efficiency, and to be able to obtain a high-contrast image. A liquid crystal panel is a representative example of such a spatial light modulator. The liquid crystal panel includes an image display region in which are built various kinds of wirings, such as data lines, scanning lines and capacity lines, and various kinds of electronic elements, such as thin film transistors and thin film diodes. For this reason, with respect to each pixel, the region through or by which light contributing to image display can be transmitted or reflected is restricted by the presence of the various kinds of wirings and electronic elements. The aperture ratio of each pixel is defined by the region through or by which light contributing to image display can be transmitted or reflected with respect to the region of each pixel, i.e., by the area ratio of the aperture region. Usually, the aperture ratio of a liquid crystal panel is about 70%. Also, the light from the light source made incident at the liquid crystal panel is transmitted through or reflected by an electro-optical substance layer, such as a liquid crystal layer, in a state where the light is substantially parallel light. For this reason, when the liquid crystal panel is irradiated with the substantially parallel light, of the total light amount, only the light amount corresponding to the aperture ratio of each pixel, can be used. The unused light becomes a light amount loss.
Thus, in the related art, a microlens array including microlens elements corresponding to each pixel, is formed on an opposition substrate of the liquid crystal panel. The microlens elements condense the illumination light from the light source towards the aperture regions in pixel units. The illumination light condensed by the microlens elements can be efficiently transmitted through the aperture regions of the pixels. For this reason, when a microlens array is used in a liquid crystal panel, the use efficiency of the light can be enhanced.
Thus, when the illumination light is condensed, light energy is locally concentrated with respect to an orientation film in the vicinity of the liquid crystal layer. The orientation film locally deteriorates due to the concentration of the light energy. When the orientation film deteriorates, the life of the spatial light modulator is reduced, whereby the need to extend the life cannot be satisfied. For this reason, a configuration to reduce the deterioration of the orientation film when a microlens array is used has been proposed in, for example, JP-A-2003-215592.
In the configuration proposed in JP-A-2003-215592, a light stabilizing agent is added to the orientation film to change resistance characteristics. The light stabilizing agent includes the function of enhancing the light-resistance of the orientation film.